1. Technical Field
The present disclosure relates to a device for use in orthopedic surgeries and, more specifically, to a growing spinal rod system.
2. Discussion of Related Art
The human spine is comprised of thirty-three vertebrae at birth and twenty-four as a mature adult. The vertebra includes the vertebral body and posterior elements, including the spinous process, transverse processes, facet joints, laminae, and pedicles. The vertebral body consists of a cortical shell surrounding a cancellous center. Between each pair of vertebrae is an intervertebral disc, which maintains the space between adjacent vertebrae and acts as a cushion under compressive, bending, and rotational loads and motions. A healthy intervertebral disc consists mostly of water in the nucleus pulposus, which is the center portion of the disc. The water content gives the nucleus a spongy quality and allows it to absorb spinal stresses.
Scoliosis is a medical condition whereby the spine is curved from side to side or front to back and may be rotated about its longitudinal axis. Typical treatment involves observation in order to determine the rate of progression and external bracing to help ensure any future growth of the spine follows the desired path and orientation.
Surgical intervention is warranted when the likelihood of curve or rotation progression is high or if a significant amount of pain or other general health risks are experienced. In these instances, a spinal fusion of various segments may be performed in order to stabilize the scoliotic curve. In younger patients, performing a spinal fusion is less desirable since it will interfere with the normal growth of the individual.
In an effort to maintain normal growth or height, while correcting a younger patient's abnormally curved spine, devices known as “growing spinal rods” have been developed. Growing spinal rods provide structure, stability, and correction to the spine, but also allow the spinal rod to lengthen without the need for replacing or adding devices to the original construct.
Growing spinal rod systems on the market today require a surgical procedure for manually increasing the length of the spinal rod; e.g., by loosening one or more set screws, providing distraction between two spinal rod segments, and then re-tightening. Systems such as this require a surgical procedure approximately every six months for several years.
Accordingly, a continuing need exists for a device that allows for skeletal growth and more specifically, spine growth, without repeated surgical intervention while maintaining the desired spinal correction.